Field of the Invention
Abnormal condition responsive devices such as ionization or photoelectric smoke detectors can be set to be highly sensitive so that with a smoke detector the detection of a smoldering fire can be made. With such a highly sensitive smoke detector, the number of false alarms which might be brought about by other conditions, whether it is in the detector or in the circuit, greatly increases with the highly sensitive detection device. On the other hand, if the sensitivity is low, a smoldering type fire can go undetected for a considerable period of time resulting in a buildup of a highly dangerous condition.